I lead a somewhat bifurcated creative life. As a writer of novels and short stories, I practice an art. As a writer of magazine articles and maker of documentary films, I practice a craft.

By way of definition and assignment: To me, an art is something in which its only value is aesthetic. A craft has artistic impulses, but it also has some level of utility. Sculpture and painting are arts; architecture and furniture-making are crafts. Dramatic films are an art. Documentary film is a craft. It can serve an informative, political or social purpose.

But that doesn’t mean documentaries don’t have tremendous artfulness, and some do far more than others. Michael Moore, for example, is not an artist but rather an investigator, and Ken Burns is not an artist but is a wonderful historian. Banksy is an artist when it comes to art, but when it comes to documentary film he’s not — he’s a showman, he’s a teller of tall tales, he’s a shameless self-promoter of his own work, but not an artist.

It is occurring to me more and more that James Marsh is as close to being an artist as anyone currently in the documentary form. There are others — Frederick Wiseman is, at least in my book; Barbara Kopple is; surprisingly, Errol Morris may not be (I see him more as a public intellectual).

It has to do with filmmakers imbuing stories with depth that rivals literature or serious dramatic film, and become by that depth artistic. Documentarians have a choice to go deep or go useful; happily, at this particular fork in the road, both ways can lead to wonderful films.

Call the art of documentary film “finding the bottom.” That, to me, means finding some depth that, while never overtly expressed and perhaps not always recognized consciously by the viewer, creates an emotional response that’s unexpected. Ever leave a theater feeling more moved by fact than fiction? There it is.

The very nature of documentary filmmaking is oppositional to that of fictional filmmakers, despite being the same form. Think of sculpting. In one approach — with clay — you add on until the shape is found. In the other, you chip away to the same result. Think of Michelangelo’s famous quote: “I saw the angel in the marble and carved until I set him free.” That’s you, documentary filmmaker. You have all of these facts and realities and you have to pare and pare until the essence of the story is found — and not the obvious one.

Marsh may be the most artistic of documentary filmmakers today, setting free the angels of human existence from the most extraordinary choices he makes.

Again, the notion of “bottom.” I’m reading the new biography of the writer Joseph Heller, which posits that his monumental Catch-22 was less about World War II, its purported subject, and more about the suffocating bureaucracy of 1950s corporate America, which that war’s veterans returned to. One of my favorite novels, Remains of the Day by Kazuo Ishiguro (a Japanese-born man transplanted to Britain at a young age) is not only about its starched butler, Mr. Stevens, but about something unstated but embedded in the author’s psyche: The samurai notion of selfless service to a master. It is the duality that creates the depth.

I’m hardly a lone voice praising Man on Wire, but I still think, despite its Academy Award, it wasn’t a fully appreciated film. The work was more than once referred to as a “caper film,” but that’s not where you find the bottom. I watched Man On Wire three times, trying to touch why I had such an emotional reaction. I came to realize that the film was a stark counterpoint, and nearly a psychic redeeming of, an all-time “caper” — the 9/11 attacks. The acrobat Philippe Petit’s quest to conquer the Twin Towers could not help but suggest, however subtly, the same planning, execution and finality of the terrorist attacks. Petit’s greatest day was intent completely without malice, and of an innocence that made the film speak of the endless process of seeking to repair the past. Every step of Petit’s wire walk casts a long, evocative shadow, yet 9/11 is never mentioned. We see in the scenes of Petit’s wire walks the crowds on the street, looking upwards, an image matched to those of 2001, where they would not be of wonder but of horror. The insight of the film is heartbreaking, even as we adore Petit.

If you just want a caper, look elsewhere. I did see another wonderful film, The Cove, as the ultimate caper film — no real art here, just action. It was an Ocean’s Eleven, except at the ocean. Like Eleven, it has a definable heist, and it assembles an “A-Team” kind of crew — instead of Eleven‘s acrobat/bomb expert/card sharp, Louis Psihoyos’s The Cove has the divers/techno geeks/environmentalists, all pulling off the deal against irredeemable bad guys and their clumsy henchmen. The ending, and no spoiler here, has the pat, confident last word you simply don’t find in real art.

To leave the theater Sunday night with as complicated feelings as I had watching Marsh’s latest, Project Nim, speaks to the effects of real art. The film, on its face, chronicles the life and times of a chimpanzee taught to use sign language. But I don’t think it’s what it’s really about. You could have made a lot of weak documentaries while telling the same factual story.

When critics tried to parse Hemingway’s The Old Man and The Sea as being a clever tale of Hemingway’s own struggles trying to land the big novel that evaded him later in life, he responded to the negative, saying, “The sea is the sea. The old man is an old man. The boy is a boy and the fish is a fish.” It’s possible, if Hemingway were taken to be truthful, that all the symbolism was there, but the author himself never saw it and never intentionally created it — just felt it somehow.

Maybe Marsh sees a story in which a chimp is a chimp, but I could not help thinking, in the film’s midst, of it being an allegory for the collapse of the American family structure in the late 20th century, of the differentials of power in human relationships, and of the disappointments of expectations. I thought as well of Pinnochio (Collodi’s fable, not Disney’s cartoon sanitization), and the way the experiment of an “invented boy” collapses both of his own limitations and the deep expectations put on him.

There are, of course, some deeply practical reasons Marsh chooses his topics — including the abundance of saved footage that can be used to tell a story from decades before. But as a documentarian, Marsh seems far more interested in the many layers his stories trigger, rather than having the last authoritative word so many filmmakers seek.

The most artful of documentary filmmakers will always seek out the bottom — the true resonance comes from there. In an era when reality programming uses documentary techniques to tell stories lacking human depth, it will continue to be, evermore, what distinguishes the documentary form.